Enhanced electrochemical performance of oxygen, nitrogen, and sulfur trial-doped Nypa fruticans-based carbon nanofiber for high performance supercapacitors

The utilization of biomass-derived carbon materials, which exhibit nanofiber structures and possess advantageous properties such as porosity, abundant availability, heteroatom content, and high specific surface area, is important in the development of green energy technologies and sustainability. Therefore, this research focuses on the synthesis of Nypa Fruticans Fiber (NFF)-derived carbon nanofiber materials through activation and carbonization processes as well as doping of oxygen (O), nitrogen (N), and sulfur (S) heteroatoms. O doping was carried out internally (activation process) while N-S doping was carried out externally using thiourea (0.1, 0.3 and 0.5 g) which aims to produce high physical properties of carbon electrodes (crystallinity structure, surface morphology, surface area specific) related to the performance improvement of supercapacitor cells. Furthermore, the NFF electrode with O-N-S doping has the physical properties of a low crystallinity structure, a high specific surface area of 1230.05 m2g−1 and the formation of a large number of nanofiber structures. The electrochemical properties of the NFF-03 supercapacitor cell electrode had the highest specific capacitance, specific energy, and specific power values of 430 Fg−1, 248 Wkg−1, 64 Whkg−1, respectively, at a current density of 1 Ag−1 in 1 M H2SO4 electrolyte solution, at a voltage of 1 V with doped 0.3 g of thiourea. The results of this research provide a clear reference that the trial heteroatom (O-N-S) doping process can produce high physical properties of carbon electrodes leading to increased performance of biomass-derived supercapacitor cells with a simple, relevant and low-cost synthesis strategy.